Yup, they had standardized tests even way back in the Great Depression. Fortunately, Billie Jo's good at them—she scored at the top of her class. Gold star.
When she tells Ma, Ma doesn't get excited and congratulate her, even though Billie Jo can tell she's proud of her. Daddy says that showing emotion when she reacts to things isn't "her way," but Billie Jo still wishes she would say more.